Oklo Splits First Reactor Atoms, Shifting the Risk Profile of Two Nuclear ETFs
Oklo's August 6 test reactor result reshapes the risk calculus for two nuclear ETFs that each carry the company among their top holdings.
Oklo, a publicly traded small-modular-reactor firm backed by OpenAI chief Sam Altman, achieved first fission in a test reactor on August 6 (2026-08-06), Canary Media reported — the first operational confirmation that its reactor technology functions as designed. The company had reached a valuation of nearly $24 billion and expanded its stated plans to include recycling nuclear waste, fabricating its own fuel and producing medical isotopes, all before splitting a single atom in any of its reactors.3
That gap between ambition and proof shapes how the milestone reads for the two nuclear exchange-traded funds that carry Oklo near the top of their portfolios. Oklo accounts for roughly 6.2% of the Global X Uranium ETF and approximately 4.4% of the VanEck Uranium and Nuclear ETF, according to Motley Fool analysis published August 12 (2026-08-12). The Global X Uranium ETF (URA) was trading at $44.93 as of August 17 (2026-08-17), up 0.27% on the session.5
NLR's performance record reflects the same tension. Over five years the fund delivered average annual returns of 18.4% by net asset value, according to Motley Fool data. But its shares fell about 3.9% over the most recent 12-month period, a divergence that reflects how unevenly SMR exposure has performed against the fund's larger holdings in operating nuclear assets.5
The fund's composition illustrates the split. Within NLR, Constellation Energy carries an 8.67% weighting, Cameco 7.95% and Public Service Enterprise Group 6.45%, according to Motley Fool data from August 12 (2026-08-12). Those are businesses generating cash from existing infrastructure. Oklo, at 4.4%, is a development-stage company that has now cleared its first significant technical gate.5
Oklo's stock trajectory adds weight to that distinction. As of June 2026 (2026-06-01), the company's shares were trailing the broader stock market in 2026 despite carrying a market capitalization of roughly $12 billion, Motley Fool reported. That is a steep decline from its near-$24 billion peak valuation — a gap the first-fission result may now begin to close, or may not.1,3
Fuel supply remains a constraint the test result does not resolve. Centrus Energy, which carries a 5.8% weighting in at least one nuclear sector fund, is among the few companies with regulatory approval to produce high-assay low-enriched uranium, the fuel grade required by next-generation reactors including Oklo's Aurora design. Commercial deployment depends on HALEU supply chains still being built.4
Demand projections underpin the long-range investment case. The Department of Energy expects U.S. data centers alone to add roughly 20 gigawatts of new electricity load by 2030, a figure cited in a June 2026 analysis. Even a fraction of that load directed to small nuclear would represent hundreds of Aurora-sized units, depending on configuration.2
The connection between AI infrastructure build-out and nuclear demand runs through Oklo directly. Sam Altman backed the company early, and Oklo's relationship with companies developing artificial intelligence has deepened over time, Motley Fool reported. The technology sector's push to secure long-duration baseload power is the broader mechanism driving interest in SMR developers.1,3
For holders of NLR or URA, the August 6 (2026-08-06) result narrows the gap between Oklo's operational claims and verifiable output. Commercial licensing progress and any data center supply agreements are the next milestones worth tracking — those are the signals that would justify a recovery toward the near-$24 billion peak from the roughly $12 billion market capitalization recorded in June 2026 (2026-06-01).3,5,1